Photoluminescence at room temperature and at 77K was monitored in porous material which had been doped with Er from a spun-on silica gel film. The incorporation of Er into SiO2 at the surface of porous Si, and rapid thermal processing at temperatures above 1223K, were found to be necessary for producing Er-related luminescence from porous Si. It was found that there was no Er diffusion, into monocrystalline Si, from spun-on films. The depth-dependent Er concentration in the bulk of porous Si was determined by means of secondary-neutral- and secondary-ion mass spectrometry depth profiling. Laterally resolved Er distributions in porous Si were deduced from energy-dispersive X-ray analyses.

A.M.Dorofeev, N.V.Gaponenko, V.P.Bondarenko, E.E.Bachilo, N.M.Kazuchits, A.A.Leshok, G.N.Troyanova, N.N.Vorosov, V.E.Borisenko, H.Gnaser, W.Bock, P.Becker, H.Oechsner: Journal of Applied Physics, 1995, 77[6], 2679-83